Graphene and glassy carbon meta-material, microfabrication method, and energy storage device

ABSTRACT

A meta-material is disclosed that includes a first layer composed of graphene, and one or more additional layers, each composed of glassy carbon or graphene. A method of producing an engineered material includes depositing a graphene precursor on a substrate, pyrolyzing the graphene precursor to allow the formation of graphene, depositing a glassy carbon precursor the graphene, pyrolyzing to allow the formation of glassy carbon from the glassy carbon precursor, depositing a graphene precursor on the glassy carbon, and pyrolyzing the graphene precursor to allow the formation of graphene.

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/552,324, titled “High-Performance Graphene and Glassy CarbonMaterial System,” filed Aug. 30, 2017, which is incorporated herein byreference.

STATEMENT OF GOVERNMENT SPONSORED SUPPORT

This invention was made with government support by the National ScienceFoundation (NSF). The U.S. Government has certain rights in the subjectmatter of the present disclosure.

TECHNICAL FIELD

The subject matter disclosed herein relates to glassy carbon-basedmaterials, graphene-based materials, and methods of fabrication relatedto these materials.

BACKGROUND

With the increasing proliferation of energy-hungry devices such asmobile phones and increased adoption of electrical vehicles, researchactivities in energy storage devices such as batteries and capacitorscontinue to grow. In addition, the expanding array of implantabledevices that interface with the human body and need to remain in vivofor at least 5 years (for example, pace-makers, cochlear implants, andneuro-prosthetics) may require long-lasting energy storage systems.

SUMMARY

In some example embodiments, there is provided an engineered materialcomprising a first layer composed of graphene, a second layer composedof glassy carbon, a third layer composed of glassy carbon, a fourthlayer composed of graphene, and a fifth layer composed of polyimide.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The engineered material may further be configuredsuch that the first layer is applied on the second layer. The engineeredmaterial may further be configured such that the second layer is appliedon the third layer. The engineered material may further be configuredsuch that the third layer is applied on the fourth layer. The engineeredmaterial may further be configured such that the fourth layer is appliedon the fifth layer. The engineered material may further be configuredsuch that the second layer includes a plurality of glassy carbon layers.The engineered material may further be configured such that the thirdlayer includes a plurality of glassy carbon layers. The engineeredmaterial may further be configured to include one or more electrodes ofan energy storage device. The engineered material may further beconfigured such that the one or more electrodes of the energy storagedevice may be configured to be in contact with an electrolyte. Theengineered material may further be configured such that the first layercomposed of graphene of the one or more electrodes may be in contactwith the electrolyte. The engineered material may further be configuredsuch that the first layer composed of graphene may be chemically bondedwith the second layer composed of glassy carbon and the third layercomposed of glassy carbon may be chemically bonded with the fourth layercomposed of graphene.

In some example embodiments, there is provided an engineered materialcomprising a first layer composed of graphene, a second layer composedof glassy carbon, and a third layer comprising a silicon substrate.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The engineered material may further be configuredsuch that the first layer may be applied on the second layer. Theengineered material may further be configured such that the second layermay be applied on the third layer.

In some example embodiments, there is provided a method for fabricatingan engineered material including depositing a metal layer on a siliconsubstrate, depositing a graphene precursor on the metal layer,pyrolyzing to allow the formation of a graphene from the grapheneprecursor, depositing a glassy carbon precursor on the graphene, andpyrolyzing to allow glassy carbon to form from the glassy carbonprecursor.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The method may further include yielding anengineered material comprising at least one layer composed of grapheneand at least one layer composed of glassy carbon. The method may furtherinclude depositing a metal layer on the glassy carbon, depositing agraphene precursor on the metal layer, and pyrolyzing to allow grapheneto form from the graphene precursor.

The details of one or more variations of the subject matter describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features and advantages of the subject matter describedherein will be apparent from the description and drawings, and from theclaims. While certain features of the currently disclosed subject matterare described for illustrative purposes in relation to an enterpriseresource software system or other business software solution orarchitecture, it should be readily understood that such features are notintended to be limiting. The claims that follow this disclosure areintended to define the scope of the protected subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, show certain aspects of the subject matterdisclosed herein and, together with the description, help explain someof the principles associated with the subject matter disclosed herein.In the drawings,

FIGS. 1A-1C depict microfabrication processes for producing a materialincluding graphene and glassy carbon, in accordance with some exampleembodiments;

FIG. 2 depicts another example of a microfabrication process forproducing a material including graphene and glassy carbon material, inaccordance with some example embodiments;

FIG. 3 depicts a microfabrication process for patterning a graphenelayer on glassy carbon, in accordance with some example embodiments;

FIGS. 4A-4B depict examples of graphene-glassy carbon materials, inaccordance with some example embodiments;

FIG. 5 depicts some examples of implementations includinggraphene-glassy carbon materials and implementations including glassycarbon materials, in accordance with some example embodiments;

FIG. 6 depicts examples of an energy storage device includinggraphene-glassy carbon materials, in accordance with some exampleembodiments;

FIG. 7 depicts an example of an energy storage device implemented usinggraphene-glassy carbon materials, in accordance with some exampleembodiments;

FIG. 8 depicts Raman and FTIR spectroscopy results performed on anexample energy storage device, in accordance with some exampleembodiments;

FIG. 9 depicts examples of structures, in accordance with some exampleembodiments; and

FIG. 10 depicts charge storage capabilities of materials, in accordancewith some example embodiments.

DETAILED DESCRIPTION

In some example embodiments, there may be provided a material includinga glassy carbon layer and a graphene layer. This material may also bereferred to herein as a graphene-glassy carbon material, graphene-glassycarbon meta-material, or graphene-glassy carbon hybrid material. Thesematerials may be referred to as an “engineered material” to indicatethat a fabrication technique is used to make the material.

In some example embodiments, the material may be implemented in adevice, such as an electrical device, energy storage device, and/or thelike. The use of the graphene-glassy carbon material may, in someimplementations, provide improved storage capacity, improvedcharge/discharge cycle characteristics, and a longer useful lifespan,when compared to other devices made from other materials.

For example, a graphene-glassy carbon material may include one or morelayers of glassy carbon and one or more layers of graphene which may beformed using, for example, chemical vapor deposition. The graphenelayers and glassy carbon layers may be bound at a molecular levelthrough chemical bonds including, for example, π-π interactions and/orsp³ type bonds in the out-of-plane direction. The graphene-glassy carbonmaterial may include any quantity of layers in any order. In someimplementations, the graphene and carbon layers may be alternatinglayers, one on top of the other.

In the fabrication processes described below, a process known aspyrolysis may be used to allow a material to form from a precursormaterial. According to example embodiments, using one set of conditions,pyrolysis may be used to allow glassy carbon to form from a glassycarbon precursor material. The glassy carbon precursor material may becomposed of, for example, any positive or negative photoresist derivedfrom a polymer. Commercially available glassy carbon precursors mayinclude, for example, SU-8, Shipley photoresist, polyimide, orpolymethyl methacrylate (PMMA), or any other epoxy resin material.According to another example, using a different set of conditions,pyroloysis may be used to allow graphene to form from a grapheneprecursor, such as PMMA or polyparamethyl styrene (PPMS). For each typeof material, a temperature, timing, precursor material, rampingconditions, atmosphere, and catalyst are adjusted to allow glassy carbonto form from a glassy carbon precursor, or to allow graphene to formfrom a graphene precursor. This co-fabrication process may create theconditions needed to form covalent bonds and/or x-x bonds between one ormore 2-dimensional graphene layers and one or more 3-dimensional glassycarbon layers. Table 1 below summarizes the pyrolysis conditions usedfor graphene and glassy carbon, respectively.

TABLE 1 Example pyrolysis conditions used to form glassy carbon orgraphene from precursor materials. Material Glassy Carbon Graphene Temp1000° C. 1000° C. Time 2 hours 10 mins (average) Pre-Cursor SU8 PPMSShipley Polyimide PMMA PMMA PS Ramping Vacuum to 50 mTorr Vacuum to 50mTorr Conditions Ramp over 7 hours to 1000° C.; 1000° C. for 7-20minutes under 7 Torr. keep for 2 hours; ramp down to Fast cooled byusing magnetic rod. room temp over 2 hours Forming N₂ H₂/Ar Gas H₂(200-600 sccm) & Ar (500 sccm) Catalyst None 500 nm Thin-filmNickel/Copper Notes SiO₂ > 300 nm.https://pubs.acs.org/doi/10.1021/nn202829y Sample in copper enclosure totrap O₂ and C left in the system.

As shown in Table 1, according to some embodiments, pyrolysis may allowglassy carbon to form in a nitrogen atmosphere by heating a glassycarbon precursor by ramping to about 1000° C. over a period of about 7hours, holding the temperature at about 1000° C. for about 2 hours, thenramping down to room temperature over a period of about 2 hours,although other temperatures, times, ramping conditions, and forming gasmay be used as well. For example, the hold time may vary from 3 hours to12 hours according to some example embodiments. According to exampleembodiments. Alternatively, glassy carbon may be formed from a glassycarbon precursor using laser pyrolysis.

Also shown in Table 1, pyrolysis may also allow graphene to form from agraphene precursor in a hydrogen/argon atmosphere and in the presence ofa catalyst, for example, nickel or copper by heating a grapheneprecursor material to about 1000° C., holding the temperature at 1000°C. for about 10 minutes, then allowing the material to cool, althoughother temperatures, times, ramping conditions, forming gases, andcatalysts may be used as well. For example, the hold time may range fromone second to one hour, according to some example embodiments.Alternatively, graphene may be formed from a graphene precursor usinglaser pyrolysis.

FIG. 1A depicts an example of a graphene-glassy carbon materialmicrofabrication process 100 using, for example, chemical vapordeposition (CVD).

At 102, there is shown three layers, an SiO₂ layer 160A, a metal layer160B, and a graphene precursor layer 160C. For example, a thin film ofmetal 160B, such as nickel (Ni), copper (Cu), and/or the like, may bedeposited at a thickness of about 300 nanometers (nm) on a SiO₂ wafer160A. A graphene precursor 160C, such as polymethyl methacrylate (PMMA)and/or the like, may then be deposited on the metal layer 160B.

When the layers 160A-C are formed at 102, pyrolysis, for example, asnoted above with respect to Table 1, may allow graphene to form as shownat 160D at 104. The graphene layer 160D at 104 may form from theprecursor, which in this example is polymethyl methacrylate 160C at 102,although other precursors may be used as well, such as, for example,polyparamethyl styrene (PPMS), polydimethylsiloxane (PDMS), andpoly(methyl methacrylate) (PMMA), and other epoxies.

After the formation of the graphene 160D at 104, the chamber used forthe pyrolysis may be purged. A glassy carbon precursor, such as, forexample, SU-8 (commercially available from MicroChem) may then bedeposited as a layer 160E as shown at 106. The glassy carbon precursormay be any material that can be used to form glassy carbon underpyrolysis. SU-8 is a glassy carbon precursor that is also a photoresistthat can be used for negative photolithography. Another polymer, AZ-4620(commercially available from AZ Electronic Materials) is a glassy carbonprecursor which is a photoresist that can be used for positivephotolithography.

Next, the layers shown at 106 may undergo pyrolysis, for example, asnoted above with respect to Table 1. Pyrolysis takes place in a chamberto allow the formation of glassy carbon 160F at 108 from the precursor160E at 106.

After the glassy carbon 160F at 108 has formed, the metal layer 160B maybe etched leaving a material including graphene layer 160D and a glassycarbon layer 160F at 110.

FIG. 1B depicts another example of a process 120 for fabricating agraphene-glassy carbon material. At 122, there is shown four layerscomprising a silicon (SiO₂) layer 170A, a glassy carbon precursor layer170B, such as SU-8, a graphene precursor layer 170C, such aspolyparamethyl styrene, and a metal layer 170D. In this example, theglassy carbon precursor 170B is deposited on an SiO₂ layer or wafer170A. Next, the graphene precursor 170C (which in this example ispolyparamethyl styrene (PPMS)) is deposited. A thin layer of metal, suchas nickel, 170D may then be deposited for a thickness of about 300 nm,although other thicknesses may be used as well. Next, pyrolysis, forexample, as noted above with respect to Table 1, may allow the formationof graphene 170E at 124 from the graphene precursor 170C at 122, such aspolyparamethyl styrene. After pyrolysis is complete, the chamber ispurged and the metal layer 170D at 124 is etched. Pyrolysis, forexample, as noted above with respect to Table 1, may then allow theformation of glassy carbon 170F at 128 from the glassy carbon precursor170B at 126. As shown at 128, the graphene layer 170E layered on theglassy carbon layer 170F is realized.

FIG. 1C depicts another example of a process 130 for making a grapheneand glassy carbon material. At 132, there is shown a silicon (SiO₂)layer or wafer 180A upon which there is applied a glassy carbonprecursor 180B, such as SU-8. After pyrolysis, the glassy carbon 180C at134 may form from the precursor 180B at 132. After the chamber ispurged, a thin layer of a graphene precursor 180D at 136, such aspolyparamethyl styrene (PPMS), may be deposited on the glassy carbonlayer 180C, followed by a thin layer of metal 180E, such as nickel. Themetal layer 180E may have a thickness of about 300 nm, although otherthicknesses may be implemented as well. Pyrolysis, for example, may thenallow formation of graphene 180F at 138 from the graphene precursor 180Dat 136. The metal layer 180E at 136 may then be etched, so what remainsis the graphene layer 180F and glassy carbon layer 180C on the siliconwafer (or layer) 180A at 138.

FIG. 2 depicts a further example of a process 200 for making a grapheneand glassy carbon material.

The process 200 at 210 to 240 is similar to the process described withrespect to FIG. 1A at 102 to 108. At 210, there is shown three layers,an SiO₂ layer 201A, a metal layer 201B, and a graphene precursor layer201C. For example, a thin film of metal 201B, such as nickel (Ni),copper (Cu), and/or the like, may be deposited at a thickness of about300 nanometers (nm) on a SiO₂ wafer 201A. A graphene precursor 201C,such as polymethyl methacrylate (PMMA) and/or the like, may then bedeposited on the metal layer 201B.

When layers 201A-C at 210 are formed, pyrolysis, for example, as notedabove with respect to Table 1, may allow graphene to form 201D at 220.This graphene layer 201D may form from the precursor 201C at 210, which,in this example is polymethyl methacrylate, although other precursorsmay be used as well.

After the formation of the graphene 201D, the chamber used for thepyrolysis may be purged. A glassy carbon precursor, such as SU-8, may beapplied as a layer 201E as shown at 230.

Next, the glassy carbon precursor at 201E at 230 may undergo pyrolysis,for example, as noted above with respect to Table 1, allowing theformation of glassy carbon at 201F at 240 from the glassy carbonprecursor 201E at 230.

According to some examples, one or more glassy carbon layers may beadded after the glassy carbon 201F at 240 is formed. For each additionallayer: 1) a glassy carbon precursor, such as SU-8, is deposited on theprevious glassy carbon layer, for example 201F; and pyrolysis allows theglassy carbon to form from the precursor.

After the desired glassy carbon layers have been added, a second metallayer 201G at 250 may be deposited on the glassy carbon, for example,201F. For example, a thin film of metal, such as nickel or copper, maybe deposited at a thickness of about 300 nm on the glassy carbon, forexample, 201F, although other thicknesses may be used.

After the metal layer 201G at 250 has been deposited, a grapheneprecursor 201H at 260, such as polymethyl methacrylate (PMMA) and/or thelike, may then be deposited on the metal layer 201G. Pyrolysis may thenallow graphene 2011 at 270 to form from the precursor 201H at 260.

After the formation of the graphene 2011 at 270, the chamber used forthe pyrolysis may be purged and a layer of polyimide 201J at 280 may bedeposited on the second graphene layer 2011. After the polyimide 2011 at280 has been deposited, the metal layer 201B at 280 may be etched,resulting in the graphene-glassy carbon material at 290.

FIG. 3 depicts a graphene-glassy carbon material microfabricationprocess 300 according to some example embodiments. In the example ofFIG. 3, a graphene layer may be patterned on glassy carbon using agraphene on metal (for example, copper) substrate pattern transfertechnique.

At 310, there is shown a silicon (SiO₂) layer or wafer 301A and a glassycarbon precursor 301B such as SU-8, although other precursors may beused. In this example, the glassy carbon precursor 301B is deposited onthe SiO₂ substrate 301A. When layers 301A and 301B are formed,pyrolysis, for example, as noted above with respect to Table 1, mayallow glassy carbon to form 301C at 320 from the glassy carbon precursor301B at 310, such as SU-8.

Next, a graphene precursor 301D at 330, such as, for example,polyparamethyl styrene (PPMS) is deposited. A thin layer of metal, suchas nickel, 301E may then be deposited for a thickness of about 300 nm,although other thickness may be used as well. Pyrolysis may then allowgraphene 301F at 340 to form from the graphene precursor 301D at 330,such as polyparamethyl styrene. The chamber is then purged and the metallayer 301E at 330 is etched. The graphene layer 301F at 340 may now bepatterned using photolithography. A photoresist layer 301G at 350, forexample polymethyl methylacrylate (PMMA) is deposited. Thephotolithography is used to expose and develop the photoresist layer301G, removing a portion of the graphene layer 301H at 360, resulting ina graphene-glassy carbon material which includes a patterned graphenelayer 301H at 360.

There are a variety of applications for the graphene-glassy carbonmaterials disclosed herein. For example, the graphene-glassy carbonmaterial may be used in semiconductor technology, sensors,photovoltaics, or energy storage. In semiconductors, graphene's improvedconductivity and zero band-gap along with glassy carbon's capability toform 3D and complex conducting components (for example, 3D electrodes,antennas, and resonators) may offer an improved platform for TTF(thin-film transistors), FET (field effect transistors), OFET, to name afew. The improved electrochemical sensing capability of glassy carbontogether with the improved electrical conductivity of graphene mayenable improved biochemical sensors with enhanced detectioncapabilities. In the case of energy storage, graphene layer may provideenhanced electrical conductivity while glassy carbon may enable highcharge storage capacity (CSC), when compared to other approaches.

FIG. 4A depicts a graphene-glassy carbon material 400 including agraphene layer 420 and a glassy carbon layer 430. FIG. 4B depictsanother example of a graphene-glassy carbon materials 440 having a topgraphene layer 450, a bottom graphene layer 480, and a middle layer ofglassy carbon material 460. The material 440 may also include one ormore additional glassy carbon layers 470 and/or one or more additionallygraphene layers 480. Alternatively or additionally, the material 440 mayalso include a polyimide layer 490.

FIG. 5 depicts some examples of system configured using graphene-glassycarbon materials.

Shown are a glassy carbon electrode with a graphene mesh patterned ontop of glassy carbon 520, grids of graphene conductors 530,microelectrode array with individual graphene and glassy carbonmicroelectrodes, 3D electrical/electrochemical cell with graphene layeron top of glassy carbon core 540 which may be used, for example, as abattery, and graphene wire suspended between glassy carbonmicrostructures 550.

FIG. 6 depicts energy storage devices 600 and 640 including thegraphene-glassy carbon material at electrodes 610, 620, 650, and 660.The energy storage device may be a device such as a battery, acapacitor, a super capacitor and/or the like. The energy storage device600 includes electrodes 610, 620 comprised from a graphene-glassy carbonmaterial as disclosed herein. The electrolyte 630 may include, forexample, a polymeric material such as PVA-H2SO4, and/or the like. Theenergy storage device 640 including graphene-glassy carbon materialelectrodes 650, 660 may include an electrolyte which includesphysiological fluids 680 to enable use in, for example, an implantablemedical device (e.g., pacemakers, cochlear implants, deep brainneurostimulators, and/or the like). Physiological fluids included in theelectrolyte 680 may be any fluid found in the body of a patient or testsubject, and may include, for example, extracellular fluid, interstitialfluid, and/or intracellular fluid.

FIG. 7 depicts a sample energy storage device 700 implemented asdescribed herein using the graphene-glassy carbon material. The sampleenergy storage device was subsequently characterized through Raman andFourier-transform infrared (FTIR) spectroscopy.

FIG. 8 depicts the results of the Raman and FTIR spectroscopy performedon a sample of a graphene-glassy carbon material implemented accordingto example embodiments. The Raman spectroscopy demonstrates the presenceof graphene on top of the glassy carbon layer.

FIG. 9 at 910 depicts the structure of glassy carbon, which consists ofgraphene-like layers formed into closely packed 3D ribbons which arebound to each other by sp³ bonds. This structure of glassy carbon allowsa natural link to layers of graphene through 7C-7C bonds. FIG. 9 at 920depicts the structure of graphene. FIG. 9 at 930 depicts the structureof a graphene/GCn/graphene material. The subscript ‘n’ indicates thenumber of layers of glassy carbon in the graphene-glassy carbonmaterial.

As shown in FIG. 10 at 1010 and 1020, each graphene-like ribbon found inthe glassy carbon is separated by a very small distance, on the order ofabout 3 Angstroms from the next layer through sp³ hybridization. Thismay form an efficient capacitor between each layer of ribbons, givingglassy carbon a high charge storage capacity. The electrostaticpotential of glassy carbon is depicted at 1030 with functional groupssuch as hydroxyls conducive for bonds.

These various aspects or features can include implementation in one ormore computer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichcan be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device. Forexample, the instructions for manufacturing the material may beimplemented in program code and taped out to enable manufacturing atother locations. The computer programs, which can also be referred to asprograms, software, software applications, applications, components, orcode, include machine instructions for a programmable processor, and canbe implemented in a high-level procedural and/or object-orientedprogramming language, and/or in assembly/machine language. As usedherein, the term “machine-readable medium” refers to any computerprogram product, apparatus and/or device, such as for example magneticdiscs, optical disks, memory, and Programmable Logic Devices (PLDs),used to provide machine instructions and/or data to a programmableprocessor, including a machine-readable medium that receives machineinstructions as a machine-readable signal. The term “machine-readablesignal” refers to any signal used to provide machine instructions and/ordata to a programmable processor. The machine-readable medium can storesuch machine instructions non-transitorily, such as for example as woulda non-transient solid-state memory or a magnetic hard drive or anyequivalent storage medium. The machine-readable medium can alternativelyor additionally store such machine instructions in a transient manner,such as for example, as would a processor cache or other random accessmemory associated with one or more physical processor cores.

The subject matter described herein can be embodied in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. The implementations set forth in the foregoingdescription do not represent all implementations consistent with thesubject matter described herein. Instead, they are merely some examplesconsistent with aspects related to the described subject matter.Although a few variations have been described in detail above, othermodifications or additions are possible. In particular, further featuresand/or variations can be provided in addition to those set forth herein.For example, the implementations described above can be directed tovarious combinations and subcombinations of the disclosed featuresand/or combinations and subcombinations of several further featuresdisclosed above. In addition, the logic flows depicted in theaccompanying figures and/or described herein do not necessarily requirethe particular order shown, or sequential order, to achieve desirableresults. The use of a first “A”, a second “A”, a third “A”, and so forthdoes not specify a particular order of the “A” items but is instead forpurposes of antecedent basis. Other implementations may be within thescope of the following claims.

1. An engineered material comprising: a first layer comprising graphene;a second layer comprising glassy carbon; a third layer comprising glassycarbon; a fourth layer comprising graphene; and a fifth layer comprisingpolyimide.
 2. The engineered material of claim 1, wherein the firstlayer is a top layer applied on the second layer.
 3. The engineeredmaterial of claim 2, wherein the second layer is applied on the thirdlayer.
 4. The engineered material of claim 3, wherein the third layer isapplied on the fourth layer.
 5. The engineered material of claim 3,wherein the fourth layer is applied on the fifth layer.
 6. Theengineered material of claim 1, wherein the second layer comprises aplurality of glassy carbon layers.
 7. The engineered material of claim1, wherein the third layer comprises a plurality of glassy carbonlayers.
 8. The engineered material of claim 1, wherein the engineeredmaterial is configured as one or more electrodes of an energy storagedevice.
 9. The engineered material of claim 8, wherein the energystorage device comprises a capacitor and/or super-capacitor.
 10. Theengineered material of claim 8, wherein the one or more electrodes arein contact with an electrolyte.
 11. The engineered material of claim 9,wherein the first layer comprising graphene of the one or moreelectrodes is in contact with the electrolyte.
 12. The engineeredmaterial of claim 1, wherein the first layer comprising graphene ischemically bonded with the second layer comprising glassy carbon, andwherein the third layer comprising glassy carbon is chemically bondedwith the fourth layer comprising graphene.
 13. An engineered materialcomprising: a first layer comprising graphene; a second layer comprisingglassy carbon; and a third layer comprising a silicon substrate.
 14. Theengineered material of claim 13 wherein the first layer is a top layerapplied on the second layer.
 15. The engineered material of claim 13wherein the second layer is applied on the third layer.
 16. A method forfabricating an engineered material comprising graphene and glassycarbon, the method comprising: depositing a first metal layer on asilicon wafer; depositing a first graphene precursor on the first metallayer; pyrolyzing the first graphene precursor layer to allow theformation of a first graphene layer; depositing a glassy carbonprecursor layer on the first graphene layer; pyrolyzing the glassycarbon precursor layer to allow the formation of a glassy carbon layer;and etching to remove the first metal layer.
 17. The method of claim 16,wherein the method yields the engineered material comprising at leastone layer composed of graphene and at least one layer composed of glassycarbon.
 18. The method of claim 17, further comprising: depositing asecond metal layer on the glassy carbon layer; depositing a secondgraphene precursor layer on the second metal layer; and pyrolyzing toallow the formation of a second graphene layer.